Convective-controlled double high flux hemodiafiltration (CC-DHF) was set-up using two high flux dialyzers. The convection occurred in the first while the fluid replacement took place in the second dialyzer. The system of CC-DHF basically resembled that of hemodiafiltration. CC-DHF was performed in 9 chronic hemodialysis Thai patients who had been treated with high flux hemodialysis for at least 6 months. When compared with high flux hemodialysis, CC-DHF could provide higher Kt/Vurea (2.4+/-0.4 vs. 2.0+/-0.4, p<0.05) and beta2-microglobulin clearance (106.2+/-15.4 vs. 48.9+/-6.1 ml/min, p<0.01). Following 6-month therapy of CC-HDF, the predialysis beta2-microglobulin levels were reduced by 12.7% while the values of Kt/Vurea were consistently higher than 2.7. The quality of life consistently improved during the 6 months of CC-DHF treatment. There were no differences in clinical and technical complications between CC-DHF and high flux hemodialysis. In conclusion, CC-DHF could provide performance comparable to hemodiafiltration without the need for expensive hemodiafiltration machines.